The present invention relates to a slide ring seal for sealing a pressurized media relative to a machine component, such as a shaft, and in particular to a seal including a slide ring, a bellows having one axial end connected with the slide ring and another axial end designed as a sealing member, and a compression spring arranged concentrically with respect to the slide ring and bellows and extending axially between the sealing member and the slide ring.
German Pat. No. 2,648,323 discloses a slide ring seal in which the bellows is held without tension by means of a holding cap in a centered installation position within the housing that surrounds it. Without the provision of a holding cap, the compression spring which cooperates with the bellows, usually produces tensile stresses in the rubber bellows, which over long periods of time result in damage to the bellows. To avoid this, the bellows is vulcanized in the installation position and is held in a centered installation position by means of the holding cap. This type of slide ring seal is generally suitable only for use under relatively low pressures, i.e to about 1 bar. Under greater pressures, the bellows, which is mounted without tension within the slide ring seal, would be deformed and thus destroy the equilibrium of forces within the bellows.
Bellows having a variety of contours in the region between the slide ring and the sealing member of the bellows are known in the art. For example, German Utility Model Pat. No. 1,858,504 discloses a corrugated bellows while German Pat. No. 2,225,776 and corresponding U.S. Pat. No. 3,782,735 disclose a bellows which, when seen in the longitudinal direction, has an approximately U-shaped configuration. None of these seals can be used under high pressure conditions since the bellows would be deformed and could possibly be sheared off at the projecting edges of corresponding structural components.